1. Field of the Invention
The present invention relates to a method of mapping contents having meta-information, and more particularly, to a method of and an apparatus for mapping a large number of items of contents each having meta-information to a low dimensional space such as a two dimensional plane based on the similarity of the contents. The present invention further relates to a computer program that causes a computer to perform the method of mapping contents having meta-information and a recording medium storing the same.
2. Description of the Related Art
The popularization of the Internet and the progress of database technology have enabled personal computer users to use a large number of items of contents (information such as an image, a picture, music, and text information).
As usable items of contents increase in number and variety, however, a user faces a difficulty in efficiently finding out an item of contents that the user desires to use. Users have been long in waiting for a technique that provides an intuitive and easily understandable user interface with which the content users can browse contents with only a simple operation and find the contents that the user desires to use. Especially, content providers who are working to increase the consumption of contents by users by improving the user interface with which the users select contents are also looking for an effective solution to that problem.
Conventionally, a technique in which a large number of items of contents are visually mapped in a two dimensional plane is proposed, for example, in the following document: James A. Wise, et. al. “Visualizing the non-visual: Spatial analysis and interaction with information from text documents”, Proc. of IEEE Information Visualization '95, p.51-58 (1995).
The document proposes a technique in which, in the case of text information, a characteristic vector is extracted from each item of text information by quantifying it, and a two dimensional map of the contents is generated based on a set of characteristic vectors by applying multi-dimensional scaling. This technique enables a user to search a desired item of items of contents by browsing a large number of contents mapped in accordance with their similarities in a two dimensional plane.
In the case where the contents are classified based on a prescribed classification hierarchy and a classification category of the classification hierarchy is assigned to each item of contents as meta-information, however, it is effective to use such meta-information for the search of a desired item of contents. Reflecting the meta-information in the mapping of contents makes the search of the desired item of contents easier.
If this mapping method of contents is used for the searching of web pages through a directory service provided by many portal sites, for example, a user can effectively focus on a classification category that the user is interested in.